1. Field of the Invention
The present invention relates to a method and an apparatus for maintaining fluid flow through a solenoid valve, and more particularly, to utilizing a solenoid valve assembly having at least one non-planar surface in a fluid flow channel thereof.
2. Description of the Background of the Invention
Aerosol containers are commonly used to store and dispense a product such as air freshening agents, deodorants, insecticides, germicides, cleaning agents, nasal decongestants or other nasally-introduced medicaments, bronchodilators or other medicaments delivered to or via the lungs, perfumes, a gel or any other known fluids or substances. The product forced from the container through an aerosol valve by a hydrocarbon or non-hydrocarbon propellant may be mixed or otherwise in contact with the product. Alternatively, a pressurized piston may forcibly eject the product through the aerosol valve. The product released from such containers may be in solid form, liquid form, gas form, and/or some combination or intermediate thereof.
A typical aerosol container comprises a body with an opening at a top end thereof. A mounting cup is crimped to the opening of the container. The mounting cup includes an outer wall that extends upwardly and inwardly from a base of the mounting cup. A pedestal is crimped to and extends upwardly from a central portion of the mounting cup. A valve having a valve stem is carried by the pedestal.
Often, the contents of an aerosol container are dispensed by an actuation system that controls product flow therethrough. One typical apparatus for controlling fluid flow is a solenoid valve. A solenoid valve comprises a solenoid having a core and a valve assembly operated by the solenoid coil. Specifically, electrical power is supplied to the coil, and the resulting magnetic flux moves a spring-loaded armature, thereby moving the armature out of contact with a sealing surface. This movement permits discharge of a product until electrical current is no longer supplied to the solenoid coil, whereupon the armature moves in an opposite direction, thereby returning the armature to the sealed position, terminating product flow.
In automatic actuation systems utilizing solenoid valves, the solenoid valve is typically cycled between on and off states during each of a plurality of duty cycles. Conventionally, the solenoid valve is actuated up to a maximum relatively brief period of time. This is due to the fact that when the solenoid is actuated for longer on times, a planar axial face of the armature may contact a planar top surface of the stopper, thereby forming a seal that partially or fully blocks the flow of product. While limiting on times has been effective to minimize flow interruption, it has been found desirable to provide a system that allows a solenoid valve to be actuated for longer on times. A system is presented herein that allows product to continuously flow during longer activation cycles. Portions of the plunger and/or stopper are made non-planar. The non-planar design ensures consistent flow of the product when the solenoid valve assembly is energized for actuation over any amount of time.